Hermetic compressor

ABSTRACT

A hermetic compressor comprising a pulsation damping flow path. The pulsation damping flow path is provided inside a discharge silencer, and is adapted to communicate the discharge silencer with a discharge chamber defined in a cylinder head. The pulsation damping flow path is formed to have a plurality of passages. Accordingly, by reducing a diameter of the respective passages down to a relatively small value compared to that of a conventional pulsation pipe, it is possible to considerably attenuate the pulsation of a refrigerant. Further, since the plural passages allow a constant amount of the refrigerant to continuously pass therethrough, it is possible to prevent an increase in a starting voltage of the compressor and the consumption of electricity thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.2003-58333, filed on Aug. 22, 2003 and Korean Patent Application No.2004-19460, filed on Mar. 22, 2004 in the Korean Intellectual PropertyOffice, the disclosure of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hermetic compressor, and, moreparticularly, to a hermetic compressor comprising a pulsation dampingflow path, which is defined in a discharge silencer and is adapted toattenuate a pressure pulsation of a refrigerant being discharged.

2. Description of the Related Art

In general, hermetic compressors serve to compress a refrigerant for usein refrigerators. Such a hermetic compressor comprises a driving unit,which generates driving force by electric power applied from theoutside, and a compressing unit, which compresses a refrigerant byreceiving the driving force from the driving unit.

The compressing unit comprises a cylinder formed in a cylinder block anddefining a compression chamber inside a hermetic casing, a pistonreciprocating inside the compression chamber, and a cylinder headcoupled to one side of the cylinder and internally defining a suctionchamber and discharge chamber.

Between the cylinder and the cylinder head is interposed a valve plate.The valve plate has a suction port and discharge port, which serve tocommunicate between the compression chamber and the suction anddischarge chambers, respectively. The valve plate further has a suctionvalve and discharge valve for selectively opening and closing thesuction port and discharge port, respectively.

A discharge silencer is coupled to the discharge chamber of the cylinderhead, and is adapted to attenuate the pulsation of a refrigerant beingdischarged, and noise generated during discharge of the refrigerant. Thedischarge silencer contains a pulsation pipe for attenuating thepulsation of the refrigerant.

The pulsation pipe has a multiply twisted spiral shape. One end of thepulsation pipe is welded to the cylinder head, which internally definesthe discharge chamber, and the other end of the pulsation pipecommunicates with the interior space of the discharge silencer.

With such a conventional hermetic compressor configured as stated above,the driving unit reciprocates the piston as electric power is appliedthereto, thereby allowing a refrigerant inside the compression chamberto be compressed. The compressed refrigerant is discharged into thedischarge chamber of the cylinder head, and in succession, moves intothe discharge silencer via the pulsation pipe. While passing through thepulsation pipe, the pulsation of the refrigerant is attenuated.

The pulsation pipe, applied in the conventional hermetic compressor, isconfigured so that, as the diameter of the pulsation pipe decreases, theresistance of a flow path increases, thereby correspondingly attenuatingthe pulsation of the refrigerant. However, since the pulsation pipe hasto continuously transfer a constant amount of the refrigeranttherethrough, such a reduction in diameter of the pulsation pipe haslimitations.

That is, although reducing the diameter of the pulsation pipe canconsiderably attenuate the pulsation and noise of the refrigerant, itmay cause another problem in that a starting voltage of the compressorand the consumption of electricity rise due to an increase in the flowpath resistance of the pulsation pipe.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above mentionedproblem, and an aspect of the invention is to provide a hermeticcompressor which can considerably attenuate the pulsation and noise of arefrigerant and can lower a starting voltage of the compressor and theconsumption of electricity thereof by improving the structure of apulsation damping structure defined in a discharge silencer.

In accordance with an aspect, the present invention provides a hermeticcompressor comprising: a cylinder internally defining a compressionchamber; a cylinder head coupled to one side of the cylinder andinternally defining a discharge chamber, the discharge chambercommunicating with the compression chamber; a discharge silencer coupledto the discharge chamber of the cylinder head and adapted to attenuate apulsation of a refrigerant being discharged; and a pulsation dampingflow path provided inside the discharge silencer so that one end thereofcommunicates with the discharge chamber and the other end thereofcommunicates with the interior of the discharge silencer, the pulsationdamping flow path having plural passages.

The pulsation damping flow path may have a multiply twisted spiralshape.

Both the ends of the pulsation damping flow path may take the form of asingle passage, respectively.

The pulsation damping flow path may include a plurality of hollow tubescoupled to each other.

The pulsation damping flow path may include a single tube, the interiorof the single tube being divided to define a plurality of passages.

The respective passages have substantially the same sectional area aseach other.

The respective passages have an inner diameter of 1.0 mm to 1.5 mm, alength of 70 mm to 120 mm, and the discharge silencer has a volume of 15cc to 25 cc.

BRIEF DESCRIPTION OF THE DRAWINGS

The above aspect, and other features and advantages of the presentinvention will become more apparent after reading the following detaileddescription when taken in conjunction with the drawings, in which:

FIG. 1 is a side sectional view illustrating the general structure of ahermetic compressor in accordance with the present invention;

FIG. 2 is a perspective view illustrating a cylinder head of thehermetic compressor in accordance with the present invention;

FIG. 3 is a sectional view illustrating the interior structure of adischarge silencer for the hermetic compressor in accordance with thepresent invention;

FIG. 4 is a sectional view illustrating another shape of a pulsationdamping flow path provided in the discharge silencer for the hermeticcompressor in accordance with the present invention; and

FIG. 5 is a graph illustrating experimental results obtained bymeasuring and comparing noise generated from both the hermeticcompressor in accordance with the present invention and a conventionalcompressor under the same conditions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be described indetail with reference to the annexed drawings.

Referring to FIG. 1 illustrating a hermetic compressor in accordancewith the present invention, it comprises a hermetic casing 10 whichincludes upper and lower casings 11 and 12 coupled with each other so asto internally define a hermetic interior space, a driving unit 20 whichis installed inside the hermetic casing 10 and adapted to generatepower, and a compressing unit 20 which is also installed inside thehermetic casing 10 and is adapted to compress a refrigerant by receivingpower from the driving unit 20.

The driving unit 20 includes a stator 21 fixedly mounted inside thehermetic casing 10, and a rotor 22 loosely fitted inside the stator 21and adapted to interact with the stator 21 in an electromagnetic manner.A rotating shaft 23 is coupled to the center of the rotor 22 so that itrotates along with the rotor 22. Arranged beneath the rotating shaft 23are an eccentric portion 24 installed to eccentrically rotate, and aconnecting rod 25 adapted to convert the eccentric rotation of theeccentric portion 24 into a rectilinear motion. For achieving such aconversion, one end of the connecting rod 25 is rotatably connected tothe eccentric portion 24, and the other end of the connecting rod 25 isconnected to a piston 32, which will be described hereinafter, in arotatable and rectilinear movable manner.

The compressing unit 30 includes a cylinder block 33 provided at oneside of a frame 31, a cylinder 32 provided inside the cylinder block 33and internally defining a compression chamber 32 a, a cylinder head 34internally defining a suction chamber 34 a (shown in FIG. 2) and adischarge chamber 34 b, which serve to guide the suction and dischargeof a refrigerant to and from the compression chamber 32 a, and a piston35 rectilinearly reciprocating inside the compression chamber 32 a.Between the cylinder 32 and cylinder head 34 is interposed a valve plate36, which is formed with a suction port 36 a and a discharge port 36 bfor use in selective communication between the compression chamber 32 aand the suction and discharge chambers 34 a and 34 b, respectively.

Referring to FIG. 2, a suction silencer 40 is coupled to the suctionchamber 34 a of the cylinder head 34 and is adapted to attenuate thepulsation of a refrigerant being sucked. The suction silencer 40 isinstalled at one side thereof with a suction tube 41 for guiding thesuction of the refrigerant.

In addition to the suction silencer 40, a discharge silencer 50 iscoupled to the discharge chamber 34 b of the cylinder head 34 and isadapted to attenuate the pulsation and noise of a refrigerant beingdischarged. The refrigerant, after passing through the dischargesilencer 50, is discharged to the outside via a discharge tube 41. Thedischarge tube 41 is installed at one side of the discharge silencer 50so as to communicate with it.

Explaining the discharge silencer 50 in detail with reference to FIG. 3,it takes the form of a cylinder in which a pulsation damping flow path52 is provided. The pulsation damping flow path 52 is adapted to guidethe refrigerant discharged from the discharge chamber 34 b of thecylinder head 34 into the discharge silencer 50, and to attenuate thepulsation of the refrigerant.

The pulsation damping flow path 52 is formed by multiply twisting a pairof coupled hollow tubes 52 a and 52 b in a spiral shape. In this case,the hollow tubes 52 a and 52 b are coupled to each other by brazing.Preferably, the hollow tubes 52 a and 52 b have substantially the samesectional area as each other.

Although the pulsation damping flow path 52 comprises the pair of thehollow tubes 52 a and 52 b, in order to secure more smooth inlet andoutlet of a refrigerant, both ends of the pulsation damping flow path 52take the form of a single tube 52 c. One end of the pulsation dampingflow path 52 is fixedly welded to the cylinder head 34 so as tocommunicate with the discharge chamber 34 b, and the other end of thepulsation damping flow path 52 communicates with the interior space ofthe discharge silencer 50.

In the present embodiment, the pair of the hollow tubes 52 a and 52 bare provided to constitute the pulsation damping flow path 52, but theremay be provided two or more hollow tubes.

Referring to FIG. 4 illustrating another pulsation damping flow path,which is designated as reference numeral 53, it may include a singletube 53 a, and the interior of the single tube 53 a may be divided intoplural passages 53 b and 53 c. In this case, the plural passages 53 band 53 c have the same sectional area and length as each other.

Now, the operation and effects of the hermetic compressor in accordancewith the present invention will be explained.

When electric power is applied to the driving unit 20, the rotatingshaft 23 rotates along with the rotor 22, and then, the eccentricportion 24 rotates in an eccentric manner according to the rotation ofthe rotating shaft 23. By virtue of the eccentric portion 24, the piston32 reciprocates inside the compression chamber 32 a, thereby allowing arefrigerant drawn from the suction chamber 34 a of the cylinder head 34to be compressed and then the compressed refrigerant to be discharged.

The refrigerant discharged into the discharge chamber 34 b moves intothe discharge silencer 50 by passing through the pulsation damping flowpath 52. Since the pulsation damping flow path 52 comprises the pluralhollow tubes 52 a and 52 b, by reducing the diameter of the hollow tubes52 a and 52 b, the pulsation damping flow path 52 can considerablyattenuate the pressure pulsation of the refrigerant while maintaining aflow rate of the refrigerant passing through the pulsation damping flowpath 52 at a constant level.

Accordingly, the pressure pulsation and noise of the refrigerant beingdischarged to the outside of the compressor can be attenuated, resultingin a stable and quite operation of the compressor.

From an experiment performed by the inventors of the present inventionunder the assumption that the pulsation damping flow path 52 comprisesthe pair of the same hollow tubes 52 a and 52 b, it has been found thatit can simultaneously attenuate the pulsation and noise of a refrigerantas well as a starting voltage of the compressor and the consumption ofelectricity when an inner diameter and length of the hollow tubes 52 aand 52 b and a volume of the discharge silencer 50 are in the followingranges: a) the inner diameter of the hollow tubes: 1.0 mm to 1.5 mm, b)the length of the hollow tubes: 70 mm to 120 mm, and c) the volume ofthe discharge silencer: 15 cc to 25 cc.

FIG. 5 is a graph illustrating experimental results obtained bymeasuring and comparing noise generated from the hermetic compressor inaccordance with the present invention, wherein respective components areconfigured according to the above enumerated dimensions, and aconventional compressor under the same conditions.

As can be seen from the graph, compared to the conventional compressor,the hermetic compressor according to the present invention achieves aconsiderable reduction in noise generated in a low frequency band lessthan 1 KHz, which tends to resonate other components of refrigerators.

As apparent from the above description, in accordance with the hermeticcompressor of the present invention, a pulsation damping flow path,which is provided in a discharge silencer and is adapted to communicatea discharge chamber defined in a cylinder head with the interior of thedischarge silencer, is configured to have plural passages.

With such a configuration, by reducing a diameter of the respectivepassages down to a relatively small value compared to that of aconventional pulsation pipe, it is possible to considerably attenuatethe pulsation of a refrigerant. Further, the plural passages areconfigured to enable a constant amount of the refrigerant tocontinuously pass therethrough, thereby being capable of preventing anincrease in a starting voltage of the compressor and the consumption ofelectricity thereof.

Although the preferred embodiments of the invention have been disclosedfor illustrative purposes, those skilled in the art will appreciate thatvarious modifications, additions and substitutions are possible, withoutdeparting from the scope and spirit of the invention as disclosed in theaccompanying claims.

1. A hermetic compressor comprising: a cylinder internally defining acompression chamber; a cylinder head coupled to one side of the cylinderand internally defining a discharge chamber, the discharge chambercommunicating with the compression chamber; a discharge silencer coupledto the discharge chamber of the cylinder head and adapted to attenuate apulsation of a refrigerant being discharged; and a pulsation dampingflow path provided inside the discharge silencer so that one end thereofcommunicates with the discharge chamber and the other end thereofcommunicates with the interior of the discharge silencer, the pulsationdamping flow path having plural passages.
 2. The compressor according toclaim 1, wherein the pulsation damping flow path has a multiply twistedspiral shape.
 3. The compressor according to claim 1, wherein both theends of the pulsation damping flow path take the form of a singlepassage, respectively.
 4. The compressor according to claim 1, whereinthe pulsation damping flow path includes a plurality of hollow tubescoupled to each other.
 5. The compressor according to claim 1, whereinthe pulsation damping flow path includes a single tube, the interior ofthe single tube being divided to define a plurality of passages.
 6. Thecompressor according to claim 1, wherein the respective passages havesubstantially the same sectional area as each other.
 7. The compressoraccording to claim 6, wherein the respective passages have an innerdiameter of 1.0 mm to 1.5 mm, a length of 70 mm to 120 mm, and thedischarge silencer has a volume of 15 cc to 25 cc.